Association between sodium–glucose cotransporter-2 (SGLT2) inhibitors and macular degeneration in patients with diabetes

Aims: Evidence showed that SGLT2 inhibitors have greater protective effects against retinal diseases compared to other hypoglycemic agents. Thus, we explore the association between SGLT2 inhibitor usage and macular degeneration (MD) in Taiwanese patients with diabetes. Methods: The National Health Insurance (NHI) program's claim data are released as the National Health Insurance Research Database (NHIRD). This database covers more than 99% of the residents in Taiwan. We included data on patients who were newly diagnosed with type 2 diabetes mellitus (ICD-9-CM: 250, exclude 250.1x; ICD-10-CM: E11), with an age at diagnosis of over 20 years as our study population. Patients who received (sodium-glucose cotransporter 2 inhibitor) SGLT2i (ATC code: A10BK) over 90 days in 2016–2019 were defined as the SGLT2i cohort. Conversely, patients who did never received SGLT2i were defined as the non-SGLT2i cohort. The exclusion criteria were having MD before the index date, receiving SGLT2i within 1–89 days, and missing data on sex, age, or days of SGLT2i usage. Two cohorts were matched by 1:1 propensity score matching, which was based on age, sex, payroll bracket grade, urbanization, comorbidities, and medications. Results: Compared to non-SGLT2i cohort, patients who received SGLT2i had a significantly lower risk of MD (adjusted hazard ratio = 0.70, 95%CI = 0.66–0.75). Conclusions: We found that SGLT2is has a strong protective effect against MD in patients with diabetes. SGLT2is may have benefits beyond glycemic control in patients with DR. However, additional clinical and experimental studies are required.